Spark plug



July 9, 1935. MCK, FIELD 2,007,948

SPARK PLUG Filed Feb. 6. 1934 www @24 LZ ayez e Zcz ildfozncl Patented July 9, 1935 UNITED STATES PATENT OFFICE SPARK PLUG(v Lloyd McKinsey Field, Cleveland, Ohio Application February 6, 1934, Serial No. 709,962

7 Claims.

This invention relates to spark plugs, and more particularly to spark plugs of the valve type for receiving air.

The main object of the invention is to provide 5 a spark plug of said character, which admits outside air and thereby the electrodes and other exposed parts are kept clean of carbon and also cooled.

Another object of the invention is to provide a spark plug of said character, in which the valve is of special design and light in weight and therefore quick and positive in action. A

A further object of the invention is to provide a spark plug of said character, which consists of few parts, is simple in construction and inexpensive to manufacture.

For a clear understanding of the invention, the same will be hereinafter fully described with reference to the accompanying drawing, and the 20 novel features thereof will be particularly pointed out in the appended claims.

In the drawing, Figure l is a longitudinal sectional view of a spark plug constructed in accordance with my invention, y Fig. 2 is a similar view, on an enlarged scale, of the lower part of the insulator and valve structure,

Fig. 3 is a transverse sectional view, taken on line 3 3 of Fig. 2, and

Fig. 4 is a bottom plan view of the disc valve.

Referring to the drawing, I represents the metallic shell, 2 the porcelain insulator, and 3 the gland nut for retaining the insulator in the shell. The shell is threaded at 4 for attachment into the 35 cylinder of an internal combustion engine, and is provided with a shoulder at 5 for supporting the insulator 2. The lower end of the insulator preferably terminates short of the shell. A suitable gasket 1 is employed at 5 and another gasket 8 between the upper shoulder 9 of the insulator and the retaining nut 3.

The insulator 2 is provided with a longitudinal opening I0, which is reduced in diameter at its lower end, as indicated at I I, thereby forming an annular shoulder I2, and is enlarged and internally threaded at its upper end as indicated at I3. Arranged in the opening II of the insulator is a nipple I4 having an enlarged head I5 of substantially the same diameter as the opening I and forming an annular shoulder I6 which is adapted to engage the shoulder I2 of the insulator. The head i of the nipple I4 is rounding or dome shaped at Il and flat on top as indicated at I8. The nipple I4 depends below the lower end of the insulator 2 and shell I and serves as a part of the center electrode. Said member i4 is provided with a central opening I9 which extends from its flat top Il through its lower or outer end. The shell electrode is indicated by 20. Fixed in the opening I0 of the insulator 2 is a tubular member 2I by means of threads at 22 corresponding to the threads at I3, and the lower end of said member engages the head I5 of the nipple I4, thereby forming the other part of the center electrode. The opening at the lower end of the tubular member 2l above the head I5 of the nipple I4 is enlarged to provide a chamber 23 for a check valve 24. The valve 24 is a comparatively thin disc of slightly less diameter than the chamber 23 and having a shallow conical face 25, which is adapted to engage the seat 26 of the chamber 23 for closing the tubular member 2I against exit irom'the cylinder of the engine. The disc valve is provided with a recess 2l across its lower fiat face 28, which normally rests against or upon the ilat top I8 of the nipple I4, and establishes communication through the tubular member 2I and said nipple to permit the inflow of air. By making the check valve 24 of the disc type, the air or gas has a broad area. on which to act. The tubular member 2i projects above the insulator 2 and is threaded at 29 for receiving a suitable nut 30 for attachment of the electric circuit wires.

In practice, the disc valve 24 normally rests upon or against the top iS of the nipple I4. Upon the down stroke of the engine piston, cool outside air is drawn in through the tubular member 2i, chamber 23, around the valve 24 and by way oi its recess 2l to the opening i9 of the nipple, and strikes the shell electrode 2Q with intensied force due to the contracted opening oi said nipple, thereby not only cleaning said electrode of carbon but cooling same and also the spark plug itself. Upon the up or compression stroke of the piston, the valve 24 is forced quickly and positively against its seat 26 thereby closing the tubular member 2i and preventing loss oi pressure in the cylinder.

From the drawing and description, it is seen that this spark plug cooled and the electrode thereof both cooled and cleaned by the intensied inow of outside air, and that the light disc check valve acts quickly and positively to prevent loss of compression or to admit the outside air upon the intake stroke of the piston.

It will be understood that slight changes in the details of construction may be made within the scope of the claims. l

l-Iaving fully described my invention, what I claim is:

1. A spark plug comprising a shell, an insulator retained within the shell, a tubular electrode in the insulator, a valve arranged Within sai electrode, and` said valve being a disc.

2. A spark plug comprising a shell, an insulator retained within the she1l,'a tubular electrode in the insulator, a valve arranged within said electrode, and said valve being a thin disc of light weight.

3. A spark plug comprising a shell, an insulator retained within the shell, the insulator having a longitudinal opening, a nipple in and supported by the insulator, a tubular member in the insulator in contact with the nipple, and a valvev Compression.

5. A spark plug comprising a shell, an insulator retained within the shell, the insulator having a longitudinal opening, a nipple in the insulator, a tubular member in the insulator inv contact with said nipple, the tubular member adjacent said nipple being provided with a chamber, a disc valve` in the chamber, and the valve having one face adapted to close said member and another face provided with means for permitting inow of air from said member through said nipple- 6. A spark plug comprising a shell,.an insulator retained within the shell, the insulator having a longitudinal opening, a nipple in the insulator, a tubular member in the insulator in contact with said nipple, the tubular member adjacent said nipple being provided with a chamber, the chamber having a seat, a disc valve in the chamber, the valve having a face adapted to engage said seat and an opposite face adapted to engage said nipple, and the last mentioned face of said valve having a transverse recess adapted to permit communication from said chamber through said nipple.

7. A spark plug comprising a shell, an insulator retained within the shell, the insulator having a longitudinal opening, the insulator having an annular shoulder, a nipple, the nipple being supported by said shoulder, a tubular member in the insulator and in contact with and pressing said nipple against said shoulder, and a valve adapted to close said tubular member.`

' A LLOYD M. FIELD. 

